Conventionally, in order to connect superconducting wires, electrical connection has been carried out as follows. For example, as shown in FIG. 8A, FIG. 8B and FIG. 8C, a superconducting wire 100 which is cut in a short length for connecting is joined to a portion where ends of superconducting wires 10 abut on each other by soldering or spot welding such that the superconducting wire 100 and the superconducting wires 10 are stuck together.
Such connection structure is also disclosed in Patent Document 1 for example (see FIG. 3 in Patent Document 1).
Also, it is known that a superconducting film is deposited on a portion where ends of superconducting wires abut on each other (see Patent Documents 2 and 3 for example). It is also known that a connection superconducting wire is stuck to a portion of a superconducting wire where a surface metal layer is removed and then the connection superconducting wire is covered with the surface metal layer which was once removed. Thereby the connection superconducting wire is joined to the superconducting wire (see Patent Document 4 for example).